A pair of Shenzhou 14 astronauts outside Tiangong during the mission's third EVA on Nov. 16, 2022. Credit: CMSA

HELSINKI — China intends to use its newly-completed Tiangong space station to test key technologies required for space-based polar power, according to a senior space official.

Robotic arms already operating on the outside of Tiangong will be used to test on-orbit assembly of modules for a space-based solar power test system, Yang Hong, chief designer of the Tiangong space station said in a presentation at the ongoing China Space Conference.

The test system will then orbit independently and deploy its solar arrays and other systems. It is likely to test and verify capabilities such as power generation, conversion and transmission.

The test will be designed to “promote breakthroughs in individual technologies, accumulate on-orbit experimental data, and make contributions to the realization of carbon peak and carbon neutrality,” Yang told CCTV. 

In 2020 China announced targets of peak carbon emissions by 2030, and carbon neutrality in 2060.

Yang noted that SBSP is one pathway to new, green energy, but that such a project still faces many technical challenges. Work is underway however.

The China Academy of Space Technology (CAST), the country’s main, state-owned spacecraft maker which made the modules for Tiangong, earlier stated that it plans to conduct a “Space high voltage transfer and wireless power transmission experiment” in low Earth orbit in 2028.

This first phase test is to be followed by a second phase experiment conducted in geostationary orbit, requiring accurate energy transmission over a distance of 35,800 kilometers to Earth, according to earlier presentations.

Phases 3 and 4, in 2035 and 2050 respectively will aim for energy generation of 10 MW and 2 gigawatts, requiring leaps in capabilities in power transmission, orbital assembly capabilities, beam steering accuracy and transmission architecture.

 Long Lehao, chief designer of China’s Long March rocket series and a SBSP advocate, said in June 2021 that the potential project would use the in-development Long March 9 super heavy-lift rocket to send the requisite infrastructure into geostationary orbit. 

China recently apparently scrapped plans for an early, expendable Long March 9 concept, instead looking to transition to a reusable version. 

China’s Xidian University in June completed a 75-meter-high steel structure facility which it calls the world’s first full-link and full-system ground test system for SBSP.

In another possibly related development, research into construction of kilometer-scale objects in orbit received funding last year. Such work could help to address the major challenge of assembling the giant arrays needed for solar power collection and transmission arrays.

Space-based solar power faces major challenges including economic feasibility and manufacturing costs, cheap and reliable launch services, and efficient and safe energy transmission.

Andrew Jones covers China's space industry for SpaceNews. Andrew has previously lived in China and reported from major space conferences there. Based in Helsinki, Finland, he has written for National Geographic, New Scientist, Smithsonian Magazine, Sky...